An organic light-emitting diode (simply referred to as OLED) display panel is produced by sequentially forming an anode, a hole injection layer, a hole transport layer, an organic material layer, an electron transport layer, an electron injection layer, a cathode, and the like on a base substrate. Here, the organic material layer may be produced by using an ink-jet printing technique. When an organic material layer is produced by using an ink-jet printing technique, it is necessary to form a pixel defining layer on a base substrate and then ink-jet a solution of an organic light-emitting material onto the base substrate formed with the pixel defining layer to form an organic material layer.
A process for producing an organic material layer by ink-jet printing comprises an ink-jet printing process and a film forming process. In an ink-jet printing process, an ink is printed to the interior of an opening formed by a pixel defining layer. The printing precision of an apparatus will influence whether the ink will deviate from the center of a pixel. In a film forming process, an ink is allowed to form a thin film with a uniform thickness in an opening formed by a pixel defining layer, by controlling pressure, temperature, time, and the like of solvent volatilization.